WordPress plugin – Amazon products

My first question is are variables used in forms Global and can you get their values with the GET_$ command?

Not in WordPress, no. Is this related to a specific plugin?

are variables used in forms Global

No.

can you get their values with the GET_$ command?

Maybe. BUT, it’s $_GET, not GET_$. If the form is submitted through a GET request you can use $_GET, but if it’s sumbitted through a POST request (they are different) you will need to use $_POST.

My second question is how do I call the amazon_api.php file and then save the results in a table so they can be posted.

That depends totally on how you’re using that file. Is it in something that you’ve written, or a specific plugin or theme?

I would also like to add a buy now with embedded affiliateid – is all this possible?

Yes. As to how to do it… we’d need a lot more info then this.